1. Field of the Invention
The present invention relates to an ignition control device, and more particularly to an ignition control device of an engine starting system.
2. Related Art
Motorcycles are popular owing to their speed and degree of flexibility. To activate the motorcycle, both fresh air introduced from the outside and fuel are delivered to a carburetor and mixed together to form oil gas; then, the oil gas is transmitted into the engine, causing deflagration and creating dynamics to achieve the reciprocating movement of piston, thereby activating the transmission system; the rotation of the back wheels are driven by the transmission system, and the rotation of the front wheels are driven synchronously with the rotation of the back wheels; this allows the motorcycle to move forward. When the motorcycle is stopped briefly, the engine may be restarted easily after a short period of time. However, if the motorcycle is stopped for too long (generally called a cold engine), it is more difficult to start the engine when it is cold.
Referring to FIG. 1, Taiwan Patent Application No. I300821 disclosed an engine starting system 7. The engine starting system 7 includes a power unit 71, a main switch lock 70, and a sensor 72. The power unit 71 (such as a storage cell) is used for providing electrical potential and current to the whole engine starting system 7 of the motorcycle. The engine starting system 7 further includes a motor control device 73 and an ignition control device 75, wherein the motor control device 73 is used to drive a crankshaft (not shown) of the engine to rotate, and the ignition control device 75 is used to initiate the spark plug, thereby allowing the engine to continue operate by itself. The main switch lock 70 is electrically connected to the power unit 71, the motor control device 73, and the ignition control device 75. The sensor 72 is electrically connected to the main switch lock 70 and the ignition control device 75, and is electrically connected to the power unit 71 through an electrified switch 78. A sensing member 74 (such as a chip card) may be sensed by the sensor 72, thereby switching the main switch lock 70.
The motor control device 73 includes a brake lever indicator switch 731, a starting switch 733, a relay 737, and a starting motor 739. Excitation coil 735 of the brake lever indicator switch 731, the starting switch 733, and the relay 737 are serially connected to each other. A set of electrical contact points 738 of the relay 737 is electrically connected to the power unit 71 and the starting motor 739. When the brake lever indicator switch 731 and the starting switch 733 are both under conducting state, the excitation coil 735 of the relay 737 is excited, thereby activating the relay 737; whereby, the set of electrical contact points 738 will be under conducting state, allowing the power unit 71 to supply electrical power to the starting motor 739, and thereby allowing the starting motor 739 to rotate, and then driving the crankshaft of the engine to rotate.
The ignition control device 75 includes a capacitive discharge ignition (CDI) 751, a high-voltage coil 753, a spark plug 755, and an ignition signal generator 757. Wherein, the capacitive discharge ignition 751, the high-voltage coil 753, and the spark plug 755 are electrically serial-connected to each other, and the ignition signal generator 757 is electrically connected to the capacitive discharge ignition 751 in order to control the conducting time of the capacitive discharge ignition 751, thereby generating a high voltage from the high-voltage coil 753 and supplying electrical power to the spark plug 755; thus, the spark plug 755 generates an electric arc and is ignited, allowing the engine to continue the rotation by itself. The ignition signal generator 757 includes an alternating current generator (ACG) 7571 and a pulser 7573. When the engine rotates, the alternating current generator 7571 is driven to generate electrical power and transmit the electrical power to the pulser 7573. The pulser 7573 then controls the capacitive discharge ignition 751, thereby generating a high voltage from the high-voltage coil 753 and supplying electrical power to the spark plug 755; thus, the spark plug 755 generates an electric arc and is ignited.
Referring to FIG. 2, Taiwan Patent Application No. I344430 disclosed an engine structure for motorcycles. Crankshaft 81 is disposed with a flywheel 82 and a pulser 83 at the left crankshaft box thereof, wherein a bump 821 is disposed on the flywheel 82. When the crankshaft 81 rotates and drives the flywheel 82, the bump 821 is induced using the pulser 83, thereby transmitting signal from the pulser 83 to the capacitive discharge ignition, and then the capacitive discharge ignition may allow the ignition action to be performed in the spark plug.
Referring to FIG. 3, Taiwan Patent Application No. 104401 disclosed a traditional ignition device 91 (such as a capacitive discharge ignition (CDI) or a transistorized coil ignition (TCI)), a low voltage power supply 93, capacitors 96, 98, diodes 90, 92, and an electric resistor 94. The traditional ignition device 91 provides the high voltage required for allowing the gas/oil mixture at the gap of the surface 971 of a traveling spark ignition (TSI) 97 to break down or ionize (magnetic field acting increases plasma volume).
The three prior arts mentioned above all lack disclosure described as follows. When the starting motor is activated under low temperature, voltage generated by the pulser of the alternating current generator is lower than the voltage generated by pulser under normal temperature. Further, voltage at the back porch of the pulser is slightly lower than voltage at the front porch of the pulser. When voltage at the back porch of the pulser is lower than 1.2V, bipolar junction transistor (BJT) of the circuit at the back porch of the capacitive discharge ignition may not be activated effectively, such that the back porch signal produced can not transmit to the micro control unit of the capacitive discharge ignition. Since the micro control unit determines the ignition timing of the spark plug based on the back porch signal, when the rotation speed is low and the back porch signal is unstable, engine ignition malfunction may occur and thereby making it difficult to start the engine.
Therefore, an engine ignition control device is required to solve the foregoing deficiencies.